The present invention relates to a procedure for switching through individual channels or a plurality of adjacent channels between two carrier frequency systems whose transmission bands have the same frequency position and are formed according to the premodulation principle, but whose premodulation frequency positions are different.
A method for switching through between two premodulation systems is described in German Offenlegungsschrift [Laid-open Application] No. 2,449,808. An example is disclosed therein which relates to switching through between two systems in which the premodulation channel of each system lies below the transmission band. The same method can of course also be used for systems whose premodulation channels lie above the transmission band.
The methods disclosed there cannot be used without difficulty under the circumstances described above.